Familial Lichen Planus

Abstract

<h3>To the Editor.—</h3> The cause of lichen planus remains obscure. Although many theories have been put forward to explain its cause, none has been widely accepted. A viral cause has long been suspected, and psychogenic influences seem to be of striking importance in many patients. The recent demonstration of immunoglobulins in lichen planus lesions¹suggests an autoimmune pathogenesis for this disease. At present, however, there is little evidence to suggest that the disease is genetically determined. We recently had the opportunity of observing three patients who had lichen planus, each with a positive family history. <h3>Report of Cases.—Case 1.—</h3> A 16-year-old girl had multiple whitish streaks of six months' duration on the buccal mucosa. There was no involvement of the skin or nails. A biopsy specimen taken from the oral mucous membrane confirmed the diagnosis of lichen planus. While this patient was undergoing treatment, violaceous, flat-topped papular